BLOOD TREATMENT EQUIPMENT

Description

FIELD OF INVENTION

[0001] The present invention relates to a blood treatment equipment comprising a control apparatus.

[0002] More particularly, the invention is concerned with an apparatus, such as a programmable computer, capable of operating on a blood treatment equipment such as an hemodialysis or other blood treatment equipment; the programmable controller is adapted to receive entries of prescribed and measured information and to generate one or more output signals in response thereto. In general the output signals are employed to control a variable operation performed by the blood treatment equipment and hence automatically perform treatment procedure control methods.

BACKGROUND OF THE INVENTION

[0003] It is known in the art of hemodialysis and other blood treatment machines using measured values of certain parameters in order to control the working of the machine.

[0004] For instance, EP097366 and US 4508622 both disclose a device provided with two conductivity cells 32,50 on the dialysis liquid side; one cell operates upstream the dialyzer and the other downstream the dialyzer. The two cells are able to measure conductivity of the dialysis liquid or sodium concentration. The measured data of detectors are compared and eventually used to control the composition of the dialysis solution.

[0005] In Gambro EP0330892, it is of advantage to employ measured values of a patient's conditional values to control functional aspects of hemodialysis equipments. In this fashion, the hemodialysis equipment may be controlled dependently of specific treatment requirements of a patient. In particular, this reference teaches to determine the concentration for a certain solute in patient's blood and other important parameters as actual clearance (indicated herein as K in ml/min) or dialysance values (expressed herein as D in ml/min). If for instance the system of EP0330892 is adapted for determining sodium concentration or conductivity of patient's blood, the dialysis liquid concentration can be controlled in order to bring about an equilibrium between the conductivities of blood and dialysis liquid, thereby obtaining a control adapted to the individual which should provide comfort for the patient.

[0006] It is also known from EP0532433 a blood treatment device able to detect actual sodium dialysance and then derive urea clearance by extrapolation. Such a calculated urea clearance is then compared with a desired urea clearance value and in case of need the flow rate of the dialysis pump or of the blood pump, or the treatment time are changed. In case treatment time is changed also the UF rate of the ultrafiltration pump is modified.

[0007] On the other hand during the last twenty years a specific index, the KT/V index, has been regarded as particularly indicative of the dialysis treatment. More in detail Keshaviah and Collins (Keshaviah P, Collins A: Rapid high-efficency bicarbonate hemodialysis, Trans Am Soc Artif Intern Organs 32: 17, 1986) reported in a well documented and well designed study on short dialysis, using the KTN index as a parameter of dialysis adequacy. This index, introduced in 1985 by Gotch and Sargent (Gotch F, Sargent JA: A mechanistic analysis of the National Cooperative Dialysis Study (NCDS). Kidney Int. 28: 526, 1985) is calculated as the product of the urea clearance (K, ml/min) of the dialyser and duration of the dialysis session (T, min), divided by the distribution volume of urea (V ml). Gotch and Sargent analysed the data of the large scale National Cooperative Dialysis Study (NCDS) in the US and determined that a KTN value of 0.9-1.0 constitutes adequate dialysis therapy. Values less than 0.8 are associated with a high probability of therapy failure. Keshaviah and Collins (Keshaviah P, Collins A: Rapid high-efficency bicarbonate hemodialysis, Trans Am Soc Artif Intern Organs 32: 17, 1986) also demonstrated that short and rapid dialysis treatment is well tolerated when acetate is replaced by bicarbonate and is not associated with increased mortality and morbidity if therapy is prescribed keeping KTN greater than 1.

[0008] In view of the above works, the value D or K for a certain solute (Notice again that Durea=Kurea) have been employed to determine value K*T_i, herein indicated as dialysis dose achieved after time T_i.

[0009] The approach presently followed in the blood treatment machines available on the marketplace is to obtain a measure of and to provide information related to a total dialysis dosage K*T value delivered as time progresses during a hemodialysis treatment procedure. This measure and the information provided is essentially based on parameters including:

a prescribed duration of the treatment procedure,

the blood flow rate,

the choice of the hemodialyser

[0010] A combination of above parameters is employed to obtain a measure of the total dialysis dosage value K*T_t delivered as an integral of mean measured instantaneous clearance values measured after determined time increments, the dialysance of the chosen dialyser (which is an in vitro clearance value) and the effective treatment time. The effective treatment time is the time during which diffusive (and generally also convective) transfer of blood solutes across a semi-permeable membrane of a hemodialyser takes place.

[0011] The above procedure basically enables a measure to be made of the K*T value delivered to a patient during a hemodialysis treatment procedure.

[0012] At the end of the treatment which normally lasts a prefixed total time T_tot, the machine provides the user with the value of K*Ttot and with the value K*Ttot/ V.

[0013] This procedure, however, suffers from a number of drawbacks. Specifically, such factors as blood flow rate and effective treatment time, which are relevant to clearance, are prone to change or are difficult to follow during a hemodialysis treatment procedure. Furthermore, the dialysance or clearance capacity of hemodialyser products can change significantly during a hemodialysis treatment procedure time. Present day hemodialysis monitoring equipment and hemodialysis procedure methods may comprise means for assessing or measuring dialysis dosages delivered to a patient over determined time increments, but no means are available for controlling the dialysis dosage value actually delivered to the patient, on an ongoing bases during treatment, and for carrying out actions on the dialysis machine working parameters as a function of the detected dialysis dosage delivered to the patient.

[0014] Document EP 0 495 412 relates to the field of hemodialysis and the fact that many patients may not receive the prescribed dialysis dose Kt/V (urea), K being the clearance of urea by the dialyser, t the time and V the volume of distribution of urea.

[0015] This document describes a dialysis method providing dialysis dose by predicting a time end point for the dialysis. In this way, the dialysis dose of urea is selected by the physician, then the urea concentration is measured initially, and the end point prediction is based upon the preferred post-dialysis urea concentration and measured urea concentration values. Those data are compared, and if appropriate, dialysis should be terminated. In the event the comparison reveals that further dialysis is appropriate, a revised time end-point may be calculated.

[0016] The document WO98/55166 relates to a method and device for calculating the dialysis efficiency. The method uses urea concentration measured by a urea monitor in the effluent dialysate line for determining parameters of the dialysis as it progresses. These parameters are used for assessing the dialysis treatment on-line to determine the efficiency, the delivered dose, pre and post-treatment total urea masses in the body, urea generation rate, volume of distribution of urea in the body and further parameters. The dose of treatment can be calculated and when the desired dose has been obtained, the dialysis treatment is terminated.

[0017] So the two latest documents describe a method which measures one or more parameters during the treatment to calculate the effective dialysis dose in order to compare it with the prescribed dialysis dose.

[0018] It Is an overall objective of the present invention to secure an ongoing control over the actual total dialysis dosage delivered to a patient.

[0019] It is another object of the invention to control some parameters of a blood treatment machine as a function of the values of the dialysis dose measured in the course of the treatment.

[0020] Furthermore, it an object of the invention to provide a control apparatus and a blood treatment equipment able to coordinate achievement of the prescribed dialysis dose with substantially contemporaneous achievement of other prescription(s).

[0021] A further object is to provide a system for synchronizing achievement of a prescribed dialysis dose, of a prescribed weight loss and of a further prescribed prescription, such as concentration of a certain substance in patient's blood. Another object of the invention is to offer a system, which is adapted to reduce, if possible, the treatment time while achieving the requested prescribed results at the end of the treatment.

[0022] Moreover it is an object of the invention to provide a controller and an equipment using said controller able to display updated values for a number of parameters, on ongoing basis at regular intervals during treatment.

SUMMARY OF THE INVENTION

[0023] The above and other objects are reached by an equipment according to one or more of the appended claims.

[0024] The controller according to the invention Is adapted to receive one or more entries of measured information measured during the course of a treatment procedure, calculate from said measured information at least a significant parameter indicative of the progress of an extracorporeal blood treatment carried out by the equipment, compare said calculated significant parameter to at least a prescribed reference value for the same parameter, and to generate at least one output control signal responsive to said comparison for automatically controlling one or more operations performed by the equipment. The significant parameter can be one chosen in the group comprising:

• the actual dialysance D_Ti or clearance K_Ti of a blood treatment unit associated with the equipment for a specific solute after a time T_i elapsed from the beginning of the treatment;
• the concentration of a substance in the blood of a patient undergoing a treatment or the patient's plasmatic conductivity Cp_Ti achieved at the elapsed time T_i;
• the dialysis dose K*T_Ti achieved at the elapsed time T_i;
• the weight loss WL_Ti achieved at the elapsed time T_i;
• a parameter proportional or known function of one or more of the above parameters.

[0025] The controller is adapted for receiving measured information from a conductivity sensor operating downstream the treatment unit or from a concentration sensor, again operating downstream the treatment unit, calculates at regular time intervals the achieved value of dialysis dosage and regulates the removal rate from the second compartment in order to have achievement, at the end of the treatment, of both the total prescribed dialysis dosage value KT_p and the prescribed total weight loss WL_p.

[0026] The removal rate can be controlled by changing the speed of an ultrafiltration pump or if the equipment does not include a pump devoted to ultrafiltration only, by changing the speed of a pump associated to the waste line at the output of the second compartment.

[0027] The controller can be programmed for estimating at regular time intervals the remaining treatment procedure time T_tr or the total treatment time T_tot necessary for achieving the prescriptions.

[0028] The controller can also be programmed for keeping said rate of fluid removal UF_Ti at time T_i substantially equal to the product of a factor R, determined by the ratio between WL_p and KT_p, by the instantaneous clearance K_Ti or instantaneous dialysance value D_Ti measured at treatment time T_i. In this case the controller synchronizes two prescriptions and ends the treatment at the prescribed values are reached with no need of calculating the remaining treatment time or the treatment time at each interval.

[0029] Safety measures may be provided to avoid that the treatment time or the fluid removal from the second compartment fall outside prescribed ranges.

[0030] Note that the prescribed reference value may comprise a patient blood conductivity or concentration target Cp_end: in this case the controller is programmed for controlling the conductivity or concentration of the treatment liquid entering the second compartment as a function of a blood conductivity or concentration target Cp_end. in order to have blood conductivity or concentration for a substance reaching said conductivity or concentration target Cp_end on or before said estimated total treatment time T_tot.

[0031] Alternatively the controller is programmed for controlling the conductivity or concentration of the treatment liquid entering the second compartment for reaching said conductivity or concentration target Cp_end when another prescription is reached (for instance total prescribed weight loss or total prescribed dialysis dose), with no need of calculation of a remaining treatment time.

[0032] According to a further aspect, the controller is associated with a display screen adapted to display at the time intervals T_i one or more of the values of the group comprising:

• remaining time T_tr,
• total treatment time T_tot,
• clearance of dialysance measurements at the elapsed time T_i,
• achieved dialysis dosage KT_Ti after T_i time,
• achieved weight loss WL_Ti after T_i time,
• achieved patient's conductivity after T_i time,
• prescribed value for more of the significant parameters,
• a value proportional to one or more of the above values.

[0033] The invention furthermore concerns program storage means including a program for a programmable controller, the program when run by the controller programming the controller to carry out the steps disclosed in the claims.

[0034] An important difference between the invention as described above and approaches followed in the past is that the treatment procedure time involved in the present invention need not be a prescribed time but may be a time which is dependent on achievement of a prescribed value. Thus, in accordance with the invention, the treatment time may be controlled by measured information which can be related to a measure of an effective clearance value of a substance (usually urea is the reference substance) measured after a determined time increment during a hemodialysis treatment procedure.

[0035] Notice that clearance values are influenced by ultrafiltration, which leads to convective transfer of solutes in blood plasma across a semi-permeable membrane of a hemodialyser product into dialysis fluid. In practically all hemodialysis treatment procedures, ultrafiltration to achieve loss of excess fluid in the patient is required. The controller is therefore adapted to include or account for the convective clearance, which follows from ultrafiltration. Most preferably, therefore, the controller should be adapted to provide output information related to both the diffusive and convective clearance values or conveniently an integrated measure of these two values.

DESCRIPTION OF THE DRAWINGS

[0036] The invention will be described with reference to the accompanying exemplary drawing tables, wherein:

Fig 1 is a schematic drawing of hemodialysis equipment associated with a controller according to the invention;

Fig 2 is a flow diagram showing the working principle of a controller according to a first embodiment of the invention;

Fig 3 is a flow diagram showing the working principle of a controller according to a second embodiment of the invention;

Fig 4 is a flow diagram showing the working principle of a controller according to a third embodiment of the invention;

Fig 5 is a flow diagram showing the working principle of a controller according to a fourth embodiment of the invention;

Fig 6 and 7 are flow diagrams of routines, which can be executed by the controller of the invention as part of its working principle.

Fig 8 schematically shows a display screen that would be associated with the controller and equipment of the invention.

DETAILED DESCRIPTION

[0037] Specific embodiments of a blood treatment equipment, associated with or comprising a controller according to the invention, are described below. For the purpose of this description reference is made to a specific blood treatment equipment, namely a dialysis equipment. However the invention is not limited to such equipment and can be used in conjunction to other kinds of blood treatment machines. With reference to specification, including the accompanying schematic drawings and the claims, the symbols below will have the meanings identified as follows:

T_tot = total treatment time

T_i= elapsed treatment time, i.e. effective treatment time elapsed from the beginning of the treatment session

T_tr= remaining treatment time

T_max= maximum treatment time

T_min= minimum treatment time

D_a= average dialysance

D_Ti= actual dialysance at time T_i

K_a= average clearance

K_Ti= actual clearance at time T_i

KT= dialysis dosage value

KT_p= prescribed dialysis dosage value

KT_Ti= integrated dialysis dosage value at time T_i

WL= weight loss

WL_p= prescribed weight loss

WL_Ti= weight loss at time T_i

UF= fluid removal rate from the second compartment of the treatment unit

UF_Ti= fluid removal rate from the second compartment of the treatment unit at time T_i

[0038] Referring now to Figure 1 schematic drawing, reference numeral 1 refers generally to a blood treatment equipment, such as for instance hemodialysis equipment, comprising or associated with a controller 2, for instance a programmable controller. The equipment as shown is connected to a blood treatment unit 3, such as a hemodialyser, comprising a first or blood compartment 4 and a second or dialysate compartment 5 divided by a semi-permeable membrane 6. A blood pump 7 is provided upstream of the hemodialyzer for pumping blood from a patient along blood arterial line 8 into the blood compartment and out from the blood compartment along blood venous line 9 to drip chamber 10 and back to the patient (not shown). Of course the position and number of blood pumps and the specific treatment unit indicated in the embodiment of fig.1 are for exemplifying purpose only and are not intended to limit the scope of the invention.

[0039] Dialysate, coming for instance from a dialysate preparation section 16, is conveyed into the dialysate compartment 5 along dialysate inlet line 11 and out from the dialysate compartment along dialysate outlet line 12 in a direction counter-current to blood flow in the hemodialyzer. A fluid balancing system is responsible of controlling the amount of fluid entering the second compartment and the amount of fluid exiting the second compartment so as to create a desired weight loss rate during treatment. For instance, the balancing system may be associated to a variable speed ultrafiltration pump 13 operating on an ultrafiltration line 13a branching off line 12 and provided for pumping ultrafiltrate from blood compartment across the semi-permeable membrane into the dialysate chamber and out from the dialysate outlet line 12. The balancing system can comprise conventional means, e.g. flow meters 14, 15 located upstream and downstream of the hemodialyzer product 3 in the way shown in figure 1. The flow meters are connected to controller 2 so that the controller is able to act at least on the ultrafiltration pump and on the waste pump 12a to keep the flow rate of the fresh dialysis liquid measured by flow meter 14 equal to the used liquid flow rate measured by flow meter 15. As the ultrafiltration pump 13 branching off conduit 12 operates upstream the flowmeter 15, such pump 13 flow rate defines the weight loss rate. Other balancing systems may comprise controlling volumes and/or weights of dialysate delivered to and withdrawn from the dialysate compartment. An infusion line may also be provided with (not shown in the appended drawing tables) for injecting replacement fluid in the arterial and/or in the venous line 8, 9. The infusion line flow rate can be obtained by variable speed pumps, which can be controlled by flow meters or volumeters or weight meters associated to the infusion line. In case of use of one or more infusion lines, also the flow rate of any infusion liquid needs to be accurately controlled during treatment, in order to control the overall balance of liquid. In this respect, notice that flow rate sensors or volumetric sensors are generally used when the dialysis or the infusion line are generated online or come from a continuous source of liquid, while weight sensors are typical of embodiments wherein the liquids are withdrawn from or conveyed to containers. For instance in case of a hemodialysis circuit using a fresh dialysate bag and a waste container, it is known to use one or two separate scales associated to the containers in order to provide a controller with an information concerning the overall weight difference between the fluid entering the second compartment of the dialyzer and the fluid exiting the second compartment.

[0040] It is clear for those skilled in the art that the present invention can be used in any kind of blood treatment machine, independently from the specific balancing system.

[0041] Going now back to the detailed description of the embodiment of figure 1, the equipment 10 can be adapted to perform different treatments such as:

• conventional hemodialysis, HD, where no infusion is present and dialysis liquid circulates in the second compartment of the dialyzer (fig 1);
• hemofiltration, HF, where no dialysis liquid is present while solutes and plasma water are pumped through line 12 and substitution fluid (not shown) is infused in the extracorporeal circuit or directly into the patient;
• hemodiafiltration, HDF, which is a combination of HD and HF;
• other blood treatments in case the treatment unit is correspondingly modified.

[0042] After the above description of the general structure of equipment 1, here below a more detailed analysis of the controller 2 will be provided.

[0043] Controller 2 comprises at least a programmable microprocessor with associated memories and interfaces suitable to communicate with the components of equipment 1. Of course the present invention controller could also comprise an analogical type calculator, though this embodiment is not felt to be the most appropriate in term of costs and flexibility.

[0044] The controller 2 is adapted to receive one or more entries of measured information measured during the course of a treatment procedure. In the embodiments shown the measured information comprises the conductivity of the dialysis liquid or the concentration of the dialysis liquid for at least a substance, measured downstream the dialyzer 3, i.e. on line 12. As shown in figure 1 the controller is connected with measuring means 18 for measuring the conductivity of the treatment liquid downstream the treatment unit. Alternatively the controller may be connected to means for measuring the concentration of a substance in the treatment liquid downstream the treatment unit. Since the measured information may also comprise the conductivity of the dialysis liquid or the concentration of the dialysis liquid for at least a substance, measured upstream the dialyzer 3, i.e. on line 11, the equipment 1 of figure 1 also includes measuring means 17 for measuring at least one of the conductivity of the treatment liquid upstream the treatment unit, or of the concentration of a substance in the treatment liquid upstream the treatment unit. The measurements carried out by the measuring means 17 operating upstream the treatment unit could be substituted by set or known values of conductivity or concentration. Notice that if the measured information is the urea concentration, it is not even necessary to carry out a measurement upstream as urea is absent from fresh dialysis liquid.

[0045] In case the measuring means are devoted to measure conductivity, then each measuring means 17, 18 comprises at least a conductivity cell. If the measuring means are devoted to measure an ion's concentration then said means comprises an ion selective sensor or a urea sensor (notice again that in case of measure of a quantity absent in fresh dialysis liquid -as urea - then there is no need to use a sensor on line 11).

[0046] The controller 1 is then programmed to calculate from the measured information (for instance from the value of the conductivity upstream and downstream the treatment unit) a value of at least a significant parameter indicative of the progress of an extracorporeal blood treatment carried out by the equipment.

[0047] According to the invention the significant parameter is one chosen in the group comprising:

• the actual dialysance D_Ti or clearance K_Ti of a blood treatment unit associated with the equipment for a specific solute after a time T_i elapsed from the beginning of the treatment;
• the concentration of a substance in the blood of a patient undergoing a treatment or the patient's plasmatic conductivity Cp_Ti, achieved at the elapsed time T_i;
• the dialysis dose K*T_Ti achieved at the elapsed time T_i;
• the weight loss WL_Ti achieved at the elapsed time T_i;
• a parameter proportional or known function of one or more of the above parameters.

[0048] Finally, the controller is adapted to compare said calculated significant parameter to at least a prescribed reference value for the same parameter, and to generate at least one output control signal responsive to said comparison for automatically controlling one or more operations performed by the equipment.

[0049] For instance, the controller 1 after having compared the calculated value of one or more significant parameters with the corresponding reference value for the same parameter may generate the output control signal responsive to said comparison for automatically controlling a fluid removal rate from said second compartment. Note that the measurement of the measured information, the calculation of the significant parameter(s), and the comparison with the respective reference value are done during the treatment (or at least during an effective portion of the treatment) on an ongoing basis, at regular time intervals, as it will be described in detail here below with reference to the embodiments shown in the drawing tables. The way that is felt to be the easiest for implementing the invention provides that the time intervals are indeed constant and prefixed, for instance equal to 15 minutes each. However, the invention can be implemented also using regular but not constant time intervals: i.e. time intervals following a specified rule or rules, which the controller should know or made aware of.

[0050] In a first embodiment, the controller 2 is programmed to carry out the steps shown in figure 2.

[0051] After having started the treatment, the controller waits for a prefixed time, for instance 10 or 15 minutes, and then carries for the first time the loop shown in figure 2, loop cycle 20, which is then repeated at each successive time interval. More in detail, according to this embodiment, the controller is programmed for determining the estimated remaining treatment procedure time T_tr and/or the estimated total treatment time T_Tot as a function of a calculated value of a significant parameter at time T_i. In other words the controller is able to modify the duration of the treatment if certain actual values of parameters deemed to be significant change during treatment.

[0052] In particular, the controller according to the first embodiment receives (as a first step 21 of the loop cycle 20) the prescribed values for the dialysis dosage KTp and for the total weight loss WL_p to be achieved at the end of the treatment.

[0053] Then, as second step 22, determines the instantaneous clearance K_Ti or dialysance value D_Ti corresponding to the conductivity or concentration measurements at treatment time T_i. Then, the controller calculates the effective dialysis dosage KT_Ti achieved at time T_i (step 23). Once calculated KT_Ti, the controller proceeds with step 24 for estimating the remaining treatment procedure time T_tr as a function of said total dialysis dosage value KT_p, of the effective total dialysis dosage KT_Ti achieved by time T_i, and of the instantaneous clearance K_Ti or dialysance value D_Ti measured at treatment time T_i. As an alternative or in conjunction with the determination of the estimated remaining treatment time, the controller 2 is programmed for determining the estimated value of the total treatment time T_tot. The estimated value of the total treatment time can be calculated for instance as a function of said total dialysis dosage value KT_p, of the effective total dialysis dosage KT_i achieved by time T_i, and of the elapsed treatment time T_i.

[0054] Alternatively said controller can calculate the estimated total treatment time T_tot as sum of the elapsed treatment time T_i and of the estimated value of the remaining treatment procedure time T_tr.

[0055] Once the estimated remaining treatment time or the estimated total treatment time are know at the instant T_i, the controller proceeds with step 25 determining an actual measured total weight loss WL_Ti achieved by time T_i, and setting the fluid removal rate UF from said second compartment for achieving the prescribed total weight loss WL_p, substantially at the same time as the prescribed total dialysis dosage value KT_p is achieved.

[0056] Notice that the control on the fluid rate removal can also be done in such a way as to achieve the prescribed total weight loss some minutes before the estimated total treatment time, which as explained derives from the calculation of the actual dialysis dosage achieved at time T_i.

[0057] Once corrected, if necessary (there might be the case where the flow rate extracted from the second compartment is already well tuned), the loop ends and the controller repeats the loop starting from step 21 or from step 22 at the successive time interval, i.e. after a time which can be prefixed or calculated by the controller. In the case of figure 2 the time interval is equal to15 minutes.

[0058] Going in further detail, notice that the controller, which is programmed for controlling, on an ongoing basis, the fluid removal rate as a function of the estimated remaining treatment procedure time T_tr or of estimated total treatment time T_tot, sets the fluid removal rate UF_Ti at time T_i equal to the prescribed total weight loss WL_p less the measured weight loss WL_Ti at time T_i, divided by the estimated remaining treatment time T_tr, according to the formula:

[0059] Alternatively, the controller can be programmed for setting of the fluid removal rate UF_Ti at time T_i equal to the prescribed total weight loss WL_p less the measured weight loss WL_Ti at time T_i, divided by a difference between the estimated total treatment time T_tot and the elapsed treatment time T_t according to the formula:

[0060] As explained, the controller is programmed for recalculating and updating at regular time intervals during treatment the estimated total treatment time Ttot and/or the estimated remaining treatment time T_tr, on the basis of the value of instantaneous clearance K_Ti or dialysance D_Ti measured at the time T_i. As an alternative for determining the estimated total treatment time T_tot and/or the estimated remaining treatment time T_tr, at instant Ti, the controller could be programmed for using recent values of clearance K_Ti-k or dialysance D_Ti-k (i.e. values determined at one or more time intervals before T_i).

[0061] In order to calculate dialysance and or clearance values during treatment any known method could be suitable. A know method provides that the instantaneous clearance value K_Ti or instantaneous dialysance value D_Ti is determined at treatment time T_i, by means of the following sub-steps:

• sending at least a first liquid through the second compartment of the treatment unit,
• sending at least a second liquid through the second compartment of the treatment unit, the second liquid having conductivity or concentration for at least a solute different from that of the first liquid
• measuring the conductivity or concentration values of said substance in the treatment liquid downstream the treatment unit at least for both said first and for said second liquid,
• calculating the instantaneous clearance K_Ti or instantaneous dialysance value D_Ti at least as a function of said measured conductivity or concentration values.

[0062] Further details of the above method and variants thereof are described in detail in the following publications, which are incorporated herein by reference:

EP patent n.0547025

EP patent n.0658352

EP patent n.0920887

[0063] Each of the above references describes an alternative way for in vivo determination of the actual dialysance, blood sodium concentration and dialysis dose. Note that any method able to determine one or more of the above significant parameters can be used for the purpose of the present invention. Referring by way of non-limiting example to a first known method for determining the concentration of a substance in blood and/or the actual dialysance for said substance (described in detail in EP 0547025B1), at least two liquids differing for their respective concentration of said specific substance are sequentially circulated through the dialysate compartment 5. The first liquid can be the dialysis liquid at its normal prescribed value of concentration for the substance and the second liquid can be obtained by introducing a step or a change in the concentration of said substance at the dialyzer inlet. The step or the change has to be in someway known or measurable. Then the conductivity or concentration of the substance are measured for the first ad second liquid both upstream and downstream of the dialyzer. Note that the upstream measurements can be substituted by set reference values. Notice in this respect that if the substance is a ionic substance, then the concentration of the substance influences the conductivity of the dialysis liquid; in particular considering that conductivity is largely influenced by the concentration of sodium ions, than measure/calculation of conductivity values gives an indication of sodium concentration in blood and in the dialysis liquid. As conductivity sensors are much more convenient and easy to use than ion selective sensors for directly detecting the concentration of an electrolyte in a liquid flow, conductivity measurements are preferably used. Then by applying the following formula cited in EP 0547025B1 for the two dialysis liquids it is possible to determine the unknowns D and Cb_in (no ultrafiltration and neglecting the so-called Donnan effect):

[0064] Wherein:

Cd_out is the conductivity or concentration of sodium in used dialysis liquid

Cd_in is the conductivity or concentration of sodium in fresh dialysis liquid

Cb_in is the concentration of sodium in untreated blood

Qd is the dialysis liquid flow

D_Tt is the dialysance of the membrane for the solute sodium at time T_t (or urea clearance: notice that the size of the urea molecule being the

same as the size of the sodium molecule, the capacity for these two molecules to pass through the same predetermined membrane is consequently the same. Therefore we can establish for a same membrane, the following equation: D_sodium = K_urea ; so detection of sodium dialysance gives clearance).

[0065] Referring to the embodiment of figure 1, conductivity or sensors 17 and 18 are provided which are respectively located for measuring the conductivity of dialysate flowing to dialysate compartment 5 along dialysate inlet line 11. In detail, conductivity sensor 17 provides upstream dialysate conductivity measures C_1in, C_2in relating to the conductivity of the first and second liquid upstream the dialyzer, while conductivity sensor 18 measures the conductivities C_1out, C_2out of the first and second dialysis liquid flowing from dialysate compartment 5 along dialysate outlet line 12. The measures of conductivity (as intermittently influenced by intermittently introducing small boluses of higher or lower concentration dialysate solutions into the dialysate inlet line) are employed to determine with the above formula instantaneous sodium dialysance values (and therefore instantaneous urea clearance values K_Ti) at any point in time T_i during a hemodialysis treatment procedure or after determined time increments so that a dialysis dosage K T_Ti, delivered at time T_i, may be determined. The above equation can be written for the two dialysis liquids circulated through the dialyzer so that the two unknowns D_Ti and Cbin_i can be determined. Referring again to the drawings, the periodically measured conductivity values Cd_1in, Cd_2in and Cd_10ut, Cd_2out (1 and 2 referring to the first and second liquid respectively) are entered into the controller via lines 17a and 18a.

[0066] As mentioned the total dialysis dosage delivered up to a certain time interval is calculated and updated at each interval as function of K_Ti or D_ti values determined with any suitable method. In detail notice that the controller can be programmed to determine the effective total dialysis dosage KT_Ti value, which has been delivered at the determined effective treatment time T_i, as an integration over time of effective instantaneous clearance K_Ti or instantaneous dialysance D_Ti values determined at the various regular time intervals T_i. Alternatively, the effective total dialysis dosage KT_i value, which has been delivered at the effective treatment time T_i, could be calculated as the product of the treatment time T_i by a mean value of effective instantaneous clearance K_Ti or of instantaneous dialysance D_Ti values determined at the various regular time intervals T_i. Of course other suitable methods could be devised.

[0067] Figure 3 shows the steps, which a second embodiment of the controller 2 is programmed to carry out.

[0068] After having started the treatment, the controller waits for a prefixed time, for instance 10 or 15 minutes, and then carries out for the first time the loop cycle 30 shown in figure 3; loop cycle 30 is then repeated at each successive time interval. More in detail, according to this embodiment, the controller is not programmed for determining the estimated remaining treatment procedure time T_tr and/or the estimated total treatment time T_Tot, and as a matter of fact could be unaware of the actual duration of the treatment. The aim of the controller according to this second embodiment is to receive the prescribed parameters, i.e. the total clearance dosage value KT_p to be achieved at the end of the treatment (step 31), and a prescribed total weight loss WL_p to be achieved at the end of the treatment (step 31), and to synchronize achievement of both said parameters.

[0069] In detail the controller is programmed for determining a prescribed rate R by dividing said total weight loss WL_p to be achieved at the end of the treatment by said total dialysis dose value KT_p to be achieved at the end of the treatment, as shown in step 32.

[0070] Then, in steps 33 and 34, the controller controls the rate of fluid removal from the second compartment of the blood treatment, said controlling comprising keeping said rate of fluid removal UF_Ti at time T_i substantially equal to the product of said prescribed rate R by the instantaneous clearance K_Ti or instantaneous dialysance value D_Ti measured at treatment time T_i.

[0071] The loop is then concluded and the controller, as for the embodiment of figure 2, waits a time interval before stating again loop 30 from the step 31 or directly from step 32, if no new prescribed values shall be considered.

[0072] Notice that the instantaneous clearance K_Ti or instantaneous dialysance value D_Ti measured at treatment time T_i can be determined as for the embodiment of figure 2.

[0073] In figure 4 a further embodiment of the program steps to be followed by a controller 2 according to the present invention is shown. The philosophy of the control loop 40 of figure 4 is similar to the one of figure 20 with some further features added.

[0074] After having started the treatment, the controller waits for a prefixed time, for instance 10 or 15 minutes, and then carries out for the first time the loop shown in figure 4, loop cycle 40, which is then repeated at each successive time interval. More in detail, according to this embodiment, the controller is programmed for determining the estimated remaining treatment procedure time T_tr and/or the estimated total treatment time T_Tot as a function of a calculated value of a significant parameter at time T_i. In other words the controller is able to modify the duration of the treatment if certain actual values of parameters deemed to be significant change during treatment.

[0075] In particular, the controller according to the first embodiment receives (as a first step 41 of the loop cycle 40) the prescribed values for the dialysis dosage KT_p and for the total weight loss WL_p to be achieved at the end of the treatment, as well as prescribed values for a minimum acceptable treatment time T_min and for a maximum acceptable treatment time T_max.

[0076] Then, as second step 42, determines the instantaneous clearance K_Ti or dialysance value D_Ti corresponding to the conductivity or concentration measurements at treatment time T_i. Then, the controller calculates the effective dialysis dosage KT_Ti achieved at time T_i (step 43). Once calculated KT_Ti, the controller proceeds with step 44 for estimating the remaining treatment procedure time T_tr as a function of said total dialysis dosage value KT_p, of the effective total dialysis dosage KT_Ti achieved by time T_i, and of the instantaneous clearance K_Ti or dialysance value D_Ti measured at treatment time T_i. As an alternative or in conjunction with the determination of the estimated remaining treatment time, the controller 2 is programmed for determining the estimated value of the total treatment time T_tot. The estimated value of the total treatment time can be calculated for instance as a function of said total dialysis dosage value KT_p, of the effective total dialysis dosage KT_i achieved by time T_i, and of the elapsed treatment time T_i.

[0077] Alternatively said controller can calculate the estimated total treatment time T_tot as sum of the elapsed treatment time T_i and of the estimated value of the remaining treatment procedure time T_tr.

[0078] The controller is then programmed to carry out a sequence of operations globally indicated with 45 in figure 4 and aiming to check whether or not the estimated values of T_tr or of T_tot are within the prescribed ranges.

[0079] In detail, said controller, at each time interval, is programmed for executing the following sub-steps of step 45:

• sub-step 46: comparing the sum T_i + T_tr with a minimum treatment time T_min and with a maximum treatment time T_max
• sub-step 47: setting a total treatment time T_tot equal to the minimum treatment time T_min, if said sum is less then the minimum treatment time T_min,
• sub-step 48: setting a total treatment time T_tot equal to the maximum treatment time T_max, if said sum is more then the minimum treatment time T_max,
• sub-step 49: setting a total treatment time T_tot equal to said sum if the sum is neither less then the minimum treatment time T_min nor more then the minimum treatment time T_max

[0080] Once the total treatment time is known at the instant T_i, the controller proceeds with step 45 determining an actual measured total weight loss WL_Ti achieved by time T_i, and setting the fluid removal rate UF from said second compartment for achieving the prescribed total weight loss WL_p, substantially at the end of said treatment time T_tot. Notice that if the controller determines in step 46 that the remaining treatment time is such that a superior time limit for the whole treatment T_max cannot be fulfilled, the controller can activate an alarm procedure 52 and ask for intervention of an operator.

[0081] If vice versa the remaining treatment time is acceptable, notice that the control on the fluid rate removal can also be done in such a way as to achieve the prescribed total weight loss some minutes before the estimated total treatment time, which as explained derives from the calculation of the actual dialysis dosage achieved at time T_i.

[0082] Once corrected the fluid removal rate from the second compartment, if necessary (there might be the case where the flow rate extracted from the second compartment is already tuned), the loop ends and the controller repeats the loop starting from step 41 or from step 42 at the successive time interval, i.e. after a time which can be prefixed or calculated by the controller .In the case of figure 4 the time interval is equal to15 minutes.

[0083] Going in further detail, notice that the controller, which is programmed for controlling, on an ongoing basis, the fluid removal rate as a function of the estimated remaining treatment procedure time T_tr or of estimated total treatment time T_tot, sets the fluid removal rate UF_Ti at time T_i equal to the prescribed total weight loss WL_p less the measured weight loss WL_Ti at time T_i, divided by the estimated remaining treatment time T_tr, according to the formula:

[0084] Alternatively, the controller can be programmed for setting of the fluid removal rate UF_Ti at time T_i equal to the prescribed total weight loss WL_p less the measured weight loss WL_Ti at time T_i, divided by a difference between the estimated total treatment time T_tot and the elapsed treatment time T_t according to the formula:

[0085] As explained, the controller is programmed for recalculating and updating at regular time intervals during treatment the estimated total treatment time T_tot and/or the estimated remaining treatment time T_tr, on the basis of the value of instantaneous clearance K_Ti or dialysance D_Ti measured at the time Ti. As an alternative for determining the estimated total treatment time T_tot and/or the estimated remaining treatment time T_tr, at instant Ti, the controller could be programmed for using recent values of clearance K_Ti-k or dialysance D_Ti-k (i.e. values determined at one or more time intervals before T_i).

[0086] In order to calculate dialysance and or clearance values during treatment any known method could be suitable as for the embodiment of figure 2.

[0087] As mentioned the total dialysis dosage delivered up to a certain time interval is calculated and updated at each interval as a function of KTi or Dti values. In detail notice that the controller can be programmed to determine the effective total dialysis dosage KT_Ti value, which has been delivered at the determined effective treatment time T_i, as an integration over time of effective instantaneous clearance K_Ti or instantaneous dialysance D_Ti values determined at the various regular time intervals T_i. Alternatively, the effective total dialysis dosage KT_i value, which has been delivered at the effective treatment time T_i, could be calculated as the product of the treatment time T_i by a mean value of effective instantaneous clearance K_Ti or of instantaneous dialysance D_Ti values determined at the various regular time intervals T_i. Of course other suitable methods could be devised.

[0088] In figure 5 a variant program loop is shown, which the controller 2 can be programmed to execute. Control loop 40 of figure 5 is almost identical to the loop 40 of figure 4 and will not be described again in detail: the same reference numerals being used to identify corresponding features or steps.

[0089] As in the embodiment of figure 4, after having started the treatment, the controller waits for a prefixed time, for instance 10 or 15 minutes, and then carries out for the first time the loop shown in figure 5, which is then repeated at each successive time interval.

[0090] More in detail, according to this embodiment, the controller is programmed for determining the estimated remaining treatment procedure time T_tr and/or the estimated total treatment time T_Tot as a function of a calculated value of a significant parameter at time T_i. In other words the controller is able to modify the duration of the treatment if certain actual values of parameters deemed to be significant change during treatment.

[0091] Differently from the embodiment of figure 4, the controller programmed to execute the steps of figure 5 receives (as a first step 41 of the loop cycle 40):

• the prescribed values for the dialysis dosage KT_p and for the total weight loss WL_p to be achieved at the end of the treatment,
• prescribed values for a minimum acceptable treatment time T_min and for a maximum acceptable treatment time T_max,
• a patient blood conductivity or concentration target Cp_end,
• the urea distribution volume V₀ for the patient.

[0092] As it will appear clear the controller 2 of this embodiment is programmed not only for achieving the aims of the controller programmed according to figure 4 steps, but also for controlling the conductivity or concentration of the treatment liquid entering the second compartment as a function of said blood conductivity or concentration target Cp_end.

[0093] Indeed, in accordance with the embodiment of figure 5, the controller executes the same identical steps 42, 43,44, 45, 46, 47, 48, 49, 50, 51,52 above described with reference to figure 4 and then, after step 51, is programmed for changing, if necessary, at each time interval, the conductivity or concentration of the treatment liquid entering the second compartment in order to have blood conductivity or concentration for a substance reaching said conductivity or concentration target Cp_end on or before said estimated total treatment time T_tot (step 53 in figure 5). Notice that step 53 can equivalently be carried out before steps 50, 51, as soon as the controller has estimated a remaining treatment time or a total treatment time at time interval T_i.

[0094] The step 53 of modifying of treatment liquid conductivity or concentration Cd comprises the following sub-steps:

i. Determining a calculated value C_di of the conductivity or concentration for a substance C_d as a function of the interval target C_pi and of the measured instantaneous dialysance or clearance D_i or K_i for time Ti,

ii. Bringing the conductivity or concentration for a substance C_d of treatment liquid entering the second compartment to said calculated value C_di

[0095] In detail the determining step uses one of the following formulas wherein V₀ represents the urea distribution volume for the patient:

[0096] In the above formulas the interval target blood conductivity or concentration Cp_i for the patient's blood relating to a time interval t_i, according to the following steps:

• evaluating if the elapsed treatment time Ti is more or less of a prescribed value Tp,
• assigning as interval target blood Cpi = Cp_end + A, wherein A is a positive value, if Ti less than Tp
• assigning as interval target blood Cpi = Cp_end, if Ti more than or equal to Tp.

In the embodiment shown, the prescribed value Tp is less than Ttot an equal to T_tot reduced by one hour.

[0097] After the detailed description concerning the embodiments of figures 2,3,4 and 5, here below are disclosed further features of the invention which can be employed in any of the embodiments wherein an estimated total treatment time or an estimated remaining treatment time are being calculated in use by the controller 2.

[0098] In detail, as shown in figure 6, the controller is programmed to carry out an end treatment test 60 to check if the remaining treatment time T_tr is less than a prescribed value, for instance 15 minutes. In the negative the cycle continues with no changes while in the affirmative the removal rate at time T_i is calculated and set for the last time (blocks 25, 26; 50, 51) and an output signal is sent to an output device, such as display unit 19.

[0099] In figure 7 an alarm procedure is shown, which could be activated in case the estimated treatment time is greater than the maximum acceptable treatment time. Indeed as shown in figure 4 the controller could either assign as total treatment time the maximum treatment time and then warn the operator that the prescribed dialysis dose will not be fulfilled or put the machine in bypass mode and ask for intervention of an operator. Notice that in some circumstances the presence of bubbles in the dialysis line or other factors degrade the performances of the treatment unit, which can recover however its normal properties upon appropriate corrections are carried out. If the operator action is positive then the calculation of the estimated remaining or total treatment time is repeated. If again the problem persists no further intervention is requested, the machine is put in permanent bypass mode (lines 11 and 12 connected bypassing second compartment 5) and an alarm given.

[0100] Please also notice that in the embodiments shown the controller is programmed to generate a control signal (arrow 's' in figure 1) to automatically control the fluid removal rate from said second compartment by controlling the variable speed ultrafiltration pump 13. However the fluid removal rate from the second compartment could be controlled in a different way depending upon the hydraulic structure and configuration of the dialysis circuit.

[0101] The controller is also associated to display unit 19 which can operate as alert device, and which can be activated if the expected treatment procedure time or remaining hemodialysis treatment time are not within a prefixed range.

[0102] The display 19 is also adapted to display at the time intervals T_i one or more of the values of the group comprising:

• remaining time T_tr,
• total treatment time T_tot,
• clearance of dialysance measurements at the elapsed time T_i,
• achieved dialysis dosage KT_Ti after T_i time,
• achieved weight loss WL_Ti after T_i time,
• achieved patient's conductivity after T_i time,
• prescribed value for more of the significant parameters,
• a value proportional to one or more of the above values.

[0103] In figure 8 an embodiment of a display unit 19 is shown. The display unit comprises three fields 100, 101, 102 each of a respective colour which are controlled by controller 2 to flash when specific events occur. First field can be for instance green and flashes when the prescribed value for one or more relevant parameter is or are reached. The second field can be for instance orange and controlled to flash when the patient is close to the treatment end (block 61).

[0104] The third field, for instance red, can be controlled to flash in case of an alarm condition, for instance when the prescribed value KTp cannot be reached within a maximum acceptable treatment time (block 52).

[0105] The display unit can also comprise an area 105 including pictograms 103, 104 which can be activated to signal the two bypass modes above described, and various additional fields for displaying alphanumerical strings 106 relating to the above prescribed and achieved significant parameters.

[0106] In addition to what already described it is also convenient to shortly underline some further possible variants to the above-described embodiments. As already mentioned, the total treatment time T_tot or remaining treatment time T_tr at time T_i is regularly recalculated and updated at regular, for instance identical, time intervals during treatment, on the basis of the last or most recent instantaneous measured clearance or dialysance value D_Ti. As an alternative the remaining treatment time and therefore also the fluid removal rate from the second compartment at time Ti can be calculated as known functions of more then one measured clearance or dialysance values. Thus, any such changes in parameters which take place during a hemodialysis treatment procedure which may influence the dialysance or clearance of a hemodialyser product, such as blood flow rate, dialysis fluid flow rate, alterations in the permeability of the semi-permeable membrane of the hemodialyser product, will automatically be accounted for each time the treatment time is recalculated. This procedure of the invention accordingly provides a reliable means for securing a measure of the treatment time required to secure the prescribed dialysis dosage value KT_p.

[0107] It should also be borne in mind that it is one objective of the present invention to secure control over the actual total dialysis dosage delivered to a patient; this control can for example be achieved, in accordance with the invention, by computing a hemodialysis treatment procedure time as a function of calculated values related to one or more of the above identified significant parameters (such as an effective clearance or dialysis dosage value reached after at treatment time Ti); a basic component of such computation would comprise a determination of a treatment time as a function of such one or more calculated values. Thus, in this example, a computed total effective treatment time would need to be a function of one or more values KT_t1, KT_t2, KT_t3,---, KT_tn, calculated in vivo using any known method after determined time increments Δt = say 5 min. For practical reasons it may only be possible to obtain a first measured value after about say 15 min of effective treatment time. Presuming this to be the case, a reasonably accurate assessment of an initial clearance or dosage value KT_ti, which has been achieved during said 15 min initial treatment time can be obtained by assuming that the measured clearance value or dosage delivered, for example after a 5 min interval, will substantially equate with the clearance value delivered over the same time period before the first measurement is made. Successive measurements of clearance values would generally be at least fractionally different from one another in that these values are dependent on changes (usually lowering) of the clearance capacity of the dialyser product during a treatment procedure, changes of blood rate, possible recirculation of treated blood, presence of bubbles in the dialysis liquid, dialysis liquid flow rate, ulfrafiltration rate and other changes.

[0108] Also notice that measurements of clearance values would only be made during effective treatment times, i.e. while blood and dialysis liquid are flowing through the hemodialyser product. The controller is accordingly programmed to initiate measurements only during effective treatment times and similarly only compute or integrate effective treatment times to arrive at a computed hemodialysis treatment procedure time during effective treatment times.

[0109] It would be possible to compute a hemodialysis treatment procedure time as a function of measured values in various fashions, e.g. by reference of the difference between successive total dialysis dosage values to a reference difference value and to compute an increase or decrease in the treatment time proportional to deviations from the reference difference value. Such a procedure could for example be realised more readily if a standardised total clearance or dialysis dosage value is to be achieved.

[0110] Finally, it is to be noted that the invention relates also to program storage means including a program for the programmable controller 2; the program when executed by the controller programs the controller to perform the steps disclosed above and shown in the attached drawings. The program storage may comprise an optical data carrier and/or a magnetic data carrier and or a volatile memory support, which can be read or associated or put into communication with the controller for programming this latter.

Claims

1. A blood treatment equipment, said equipment comprising at least a treatment unit including a semipermeable membrane separating the treatment unit in a first compartment for the circulation of blood and in a second compartment for the circulation of a treatment liquid, and a controller adapted to:

- receive one or more entries of measured information measured during the course of a treatment procedure,

- calculate from said measured information a value of at least a significant parameter indicative of the progress of an extracorporeal blood treatment carried out by the equipment,

- compare said calculated significant parameter to at least a prescribed reference value for the same parameter, the prescribed reference value comprising the total dialysis dosage value KT_p to be achieved at the end of the treatment,

- generate at least one output control signal responsive to said comparison for automatically controlling one or more operations performed by the equipment,

said controller determining, at time intervals during treatment

o an instantaneous clearance K_Ti or dialysance value D_Ti measured at treatment time T_i,

o an effective total dialysis dosage KT_Ti value which has been delivered at the elapsed treatment time T_ti and

o at least one among an estimated remaining treatment procedure time T_tr and an estimated total treatment time T_tot required for achieving said prescribed total dialysis dosage value KT_p, wherein the controller is adapted to generate said output control signal responsive to said comparison for automatically controlling a fluid removal rate from said second comportment.

2. Equipment according to claim 1, wherein the significant parameter is one chosen in the group comprising:

- the actual dialysance D_Ti or clearance K_Ti of a blood treatment unit associated with the equipment for a specific solute after a time T_i elapsed from the beginning of the treatment;

- the concentration of a substance in the blood of a patient undergoing a treatment or the patient's plasmatic conductivity Cp_Ti achieved at the elapsed time T_i;

- the dialysis dose K*T_Ti achieved at the elapsed time T_i;

- the weight loss WL_Ti achieved at the elapsed time T_i;

- a parameter proportional or known function of one or more of the above parameters.

3. Equipment according to claims 1 or 2, wherein said measured information is one chosen in the group comprising:

- conductivity of the treatment liquid downstream the treatment unit;

- concentration of a substance in the treatment liquid downstream the treatment unit.

4. Equipment according to anyone of claims 1 to 5 wherein said controller is programmed for determining the estimated remaining treatment procedure time T_tr as a function of said total dialysis dosage value KT_p, the effective total dialysis dosage KT_Ti achieved by time T_i, and of the instantaneous clearance K_Ti or dialysance value D_Ti measured at treatment time T_i.

5. Equipment according to anyone of claims 1 to 3, wherein said controller is programmed for determining the estimated total treatment time T_tot as a function of said total dialysis dosage value KT_p, of the effective total dialysis dosage KT_i achieved by time T_i, and of the elapsed treatment time T_i.

6. Equipment according to claim 4, wherein said controller, at each time interval, is programmed for updating the estimated total treatment time T_tot as sum of the elapsed treatment time T_i and of the estimated value of the remaining treatment procedure time T_tr.

7. Equipment according to claim 4 or 5 wherein said prescribed parameter also comprises a prescribed total weight loss WL_p to be achieved at the end of the treatment, said controller being programmed for performing the following further steps at time intervals during treatment:

o determining of an actual measured total weight loss WL_Ti achieved by time T_i,

o setting of fluid removal rate UF from said second compartment for achieving a prescribed total weight loss WL_p substantially at the same time as the prescribed total dialysis dosage value KT_p is achieved.

8. Equipment according to claim 7, wherein it is programmed for controlling, on an ongoing basis, the fluid removal rate as a function of the estimated remaining treatment procedure time T_tr or of estimated total treatment time T_tot.

9. Equipment according to claim 8, wherein said controlling comprises setting of the fluid removal rate UF_Ti at time T_i equal to the prescribed total weight loss WL_p less the measured weight loss WL_Ti at time T_i, divided by the estimated remaining treatment time T_tr, according to the formula:

10. Equipment according to claim 8, wherein said controlling step comprises setting of the fluid removal rate UF_Ti at time T_i equal to the prescribed total weight loss WL_p less the measured weight loss WL_Ti at time T_i, divided by a difference between the estimated total treatment time T_tot and the elapsed treatment time T_t according to the formula:

11. Equipment according to anyone of claims from 1 to 10, wherein the controller is programmed for recalculating and updating at regular time intervals during treatment the estimated total treatment time T_tot and/or the estimated remaining treatment time T_tr, on the basis of the most recent value or values of instantaneous clearance K_Ti or dialysance D_Ti.

12. Equipment according to anyone of claims from 1 to 10, wherein it is programmed for recalculating and updating at regular time Intervals during treatment the effective total dialysis dosage KT_Ti value, which has been delivered at the elapsed effective treatment time T_i.

13. Equipment according to claim 1, wherein the instantaneous clearance value K_Ti or instantaneous dialysance value D_Ti is determined at treatment time T_i, by means of the following sub-steps:

- sending at least a first liquid through the second compartment of the treatment unit,

- sending at least a second liquid through the second compartment of the treatment unit, the second liquid having conductivity or concentration for at least a solute different from that of the first liquid

- measuring the conductivity or concentration values of said substance in the treatment liquid downstream the treatment unit at least for both said first and for said second liquid,

- calculating the instantaneous clearance K_Ti or instantaneous dialysance value D_Ti at least as a function of said measured conductivity or concentration values.

14. Equipment according to claim 1, wherein the effective total dialysis dosage KT_Ti value, which has been delivered at the determined effective treatment time T_i, is calculated as an integration over time of effective instantaneous clearance K_Ti or instantaneous dialysance D_Ti values determined at the various regular time intervals T_i.

15. Equipment according to claim 1, wherein the effective total dialysis dosage KT_i value, which has been delivered at the effective treatment time T_i, is calculated as the product of the treatment time T_i by a mean value of effective instantaneous clearance K_Ti or of instantaneous dialysance D_Ti values determined at the various regular time intervals T_i.

16. Equipment according to claim 12, wherein said controller is programmed for controlling the rate of fluid removal from the second compartment of the blood treatment, said controlling comprising keeping said rate of fluid removal UF_Ti at time T_i substantially equal to the product of said prescribed rate R by the instantaneous clearance K_Ti or instantaneous dialysance value D_Ti measured at treatment time T_i.

17. Equipment according to claim 1, wherein said controller, at each time interval, is programmed for:

- calculating a sum of the elapsed treatment time T_i with the calculated value of the remaining treatment procedure time T_tr.

- comparing said sum with a minimum treatment time T_min and with a maximum treatment time T_max

- setting a total treatment time T_tot equal to the minimum treatment time T_min, if said sum Is less then the minimum treatment time T_min,

- setting a total treatment time T_tot equal to the maximum treatment time T_max, if said sum is more then the minimum treatment time T_max

- setting a total treatment time T_tot equal to said sum if the sum is neither less then the minimum treatment time T_min nor more then the minimum treatment time T_max.

18. Equipment according to claim 17, wherein said prescribed parameter also comprises a prescribed total weight loss WL_p to be achieved at the end of the treatment, said controller being programmed for performing the following further steps at time intervals during treatment:

o determining of an actual measured total weight loss WL_Ti achieved by time T_i,

o setting of fluid removal rate from said second compartment for achieving a prescribed total weight loss WL_p at said total treatment time T_tot.

19. Equipment according to claim 18, wherein the controller is programmed for controlling, on an ongoing basis, the fluid removal rate UF_Ti at time T_i as a function of the total treatment time T_tot by setting the UF_Ti fluid removal rate at time T_i equal to the prescribed total weight loss WL_p less the measured weight loss WL_Ti at time T_i. divided by the difference between the calculated total treatment time T_tot and the elapsed treatment time T_i, according to the formula:

20. Equipment according to claim 18, wherein the controller is programmed for recalculating and updating the total treatment time T_tot and/or the remaining treatment time T_tr at regular time intervals during treatment, on the basis of the last or most recent instantaneous measured value or values of clearance K_Ti or dialysance D_Ti.

21. Equipment according to claim 18, wherein the controller is programmed for recalculating and updating at regular time intervals during treatment the effective total dialysis dosage KT_Ti value which has been delivered at the elapsed effective treatment time T_i.

22. Equipment according to claim 18, wherein the effective total dialysis dosage KT_i value, which has been delivered at the determined effective treatment time T_i, is calculated as an integration over time of effective instantaneous dialysis dosage values D_Ti determined at the various regular time intervals T_i.

23. Equipment according to claim 1 or 17, wherein the prescribed reference value comprises a patient blood conductivity or concentration target Cp_end, said controller being programmed for controlling the conductivity or concentration of the treatment liquid entering the second compartment as a function of said blood conductivity or concentration target Cp_end.

24. Equipment according to claim 1, wherein the prescribed reference value comprises a patient blood conductivity or concentration target Cp_end to be achieved, said controller being programmed for changing, if necessary, at each time interval, the conductivity or concentration of the treatment liquid entering the second compartment in order to have blood conductivity or concentration for a substance reaching said conductivity or concentration target Cp_end on or before said estimated total treatment time T_tot.

25. Equipment according to claim 7, wherein the prescribed reference value comprises a patient blood conductivity or concentration target Cp_end to be achieved, said controller being programmed for changing, if necessary, at each time interval, the conductivity or concentration of the treatment liquid entering the second compartment in order to have blood conductivity or concentration for a substance reaching said conductivity or concentration target Cp_end on or before said estimated total treatment time T_tot

26. Equipment according to anyone of claims from 1 to 22, wherein the prescribed reference value comprises a patient blood conductivity or concentration target Cp_end to be achieved, said controller being programmed for performing the following steps at each time Interval t_i during at least a part of said treatment:

o determining an interval target blood conductivity or concentration Cp_i for the patient's blood, relating to a elapsed time Ti

o modifying, if necessary, the conductivity or concentration for a substance C_d of treatment liquid entering the second compartment to have the patient plasmatic conductivity reaching the interval target Cp_i.

27. Equipment according to claim 26, wherein the said modifying of treatment liquid conductivity or concentration Cd comprises the following sub-steps:

i. Determining a calculated value C_di of the conductivity or concentration for a substance C_d as a function of the Interval target C_pi and of the measured instantaneous dialysance or clearance D_i or K_i for time T_i,

ii. Bringing the conductivity or concentration for a substance C_d of treatment liquid entering the second compartment to said calculated value C_di

28. Equipment according to claim 27, wherein the said determining step uses the following formula:


wherein V_o represents the urea distribution volume for the patient.

29. Equipment according to claim 27, wherein the said determining step uses the following formula:

wherein V₀ represents the urea distribution volume for the patient.

30. Equipment according to claim 26, wherein the controller is programmed for calculating said interval target blood conductivity or concentration Cp_i for the patient's blood relating to a time interval t_i, according to the following steps:

- evaluating if the elapsed treatment time Ti is more or less of a prescribed value Tp,

- assigning as interval target blood Cpi = Cp_end + A, wherein A is a positive value, if Ti less than Tp

- assigning as interval target blood Cpi = Cp_end, if Ti more than or equal to Tp.

31. Equipment according to claim 30, wherein the prescribed value Tp is less than Ttot.

32. Equipment according to claim 31, wherein the prescribed value T_p is equal to T_tot reduced by one hour.

33. Equipment according to claim 1, comprising measuring means connected to the controller for measuring at least one of:

conductivity of the of the treatment liquid downstream the treatment unit; or

concentration of a substance in the treatment liquid downstream the treatment unit.

34. Equipment according to claim 1, comprising measuring means for measuring at least one of:

conductivity of the of the treatment liquid upstream the treatment unit; or

concentration of a substance in the treatment liquid upstream the treatment unit.

35. Equipment according to claim 33, comprising measuring means for measuring comprises a conductivity cell or an ion selective sensor or a urea sensor, operating on a conduit downstream the treatment unit.

36. Equipment according to claim 34, comprising measuring means for measuring comprises a conductivity cell or an ion selective sensor, operating on a conduit upstream the treatment unit.

37. Equipment according to claim 1 also including entry means for entering prescribed reference value or values for the significant parameter or parameters.

38. Equipment according to claim 1, comprising a variable speed ultrafiltration pump, in which the controller is programmed to generate a control signal to automatically control the fluid removal rate from said second compartment by controlling the variable speed ultrafiltration pump.

39. Equipment according to claim 1, wherein the controller is associated with an alert device, and the controller is programmed to activate said alert device if the expected treatment procedure time or remaining hemodialysis treatment time are not within a prefixed range.

40. Equipment according to claim 1, in which the controller is associated with a display screen adapted to display at the time intervals T_i one or more of the values of the group comprising:

- remaining time T_tr,

- total treatment time T_tot,

- clearance of dialysance measurements at the elapsed time T_i,

- achieved dialysis dosage KT_Ti after T_i time,

- achieved weight loss WL_Ti after T_i time,

- achieved patient's conductivity after T_i time,

- prescribed value for more of the significant parameters,

- a value proportional to one or more of the above values.

41. Program storage means Including a program for a programmable controller of a blood treatment equipment according to claim 1, the program when run by the controller rendering the controller adapted to execute a method of automatically controlling one or more variable operations performed by the equipment comprising the steps of: receiving one or more entries of measured information measured during the course of a treatment procedure

- calculating from said measured information a value of at least a significant parameter indicative of the progress of an extracorporeal blood treatment carried out by the equipment,

- comparing said calculated significant parameter to at least a prescribed reference value for the same parameter, the prescribed reference value comprising the total dialysis dosage value KT_p to be achieved at the end of the treatment,

- generating at least one output control signal responsive to said comparison for automatically controlling one or more operations performed by the equipment,

- determining, at time intervals during treatment:

o an instantaneous clearance K_Ti or dialysance value D_Ti measured at treatment time T_i,

o an effective total dialysis dosage KT_Ti value which has been delivered at the elapsed treatment time T_i, and

o at least one among an estimated remaining treatment procedure time T_tr and an estimated total treatment time T_tot required for achieving

said prescribed total dialysis dosage value KT_p, - wherein the step of generating said output control signal responsive to said comparison is for automatically controlling a fluid removal rate from said second comportement.

42. Program storage means according to claim 41 comprising an optical data carrier and/or a magnetic data carrier and or a volatile memory support.

Ansprüche

1. Blutbehandlungseinrichtung, wobei die Einrichtung mindestens eine Behandlungseinheit mit einer semipermeablen Membran, die die Behandlungseinheit in eine erste Kammer zur Blutzirkulation und in eine zweite Kammer zur Zirkulation einer Behandlungsflüssigkeit teilt, und einen Controller umfasst, der angepasst ist zum:

- Empfangen von einer oder mehreren Einträgen gemessener Information, die während des Behandlungsvorgangs gemessen wurde,

- Berechnen von einem Wert mindestens eines signifikanten Parameters aus der gemessenen Information, der die Entwicklung einer durch die Einrichtung durchgeführten extrakorporalen Blutbehandlung anzeigt,

- Vergleichen des berechneten signifikanten Parameters mit mindestens einem vorgegebenen Bezugswert für denselben Parameter, wobei der vorgegebene Bezugswert den Gesamtdialysedosierungswert KT_p umfasst, der am Ende der Behandlung erreicht werden soll,

- Erzeugen von mindestens einem Ausgangssteuersignal als Reaktion auf den Vergleich, um eine oder mehrere durch die Einrichtung durchgeführten Operationen automatisch zu steuern,

wobei der Controller in Zeitintervallen während der Behandlung bestimmt:

o einen augenblicklichen Wert von Clearance K_TI oder Dialysance D_TI, der bei Behandlungszeit T_I gemessen wurde,

o einen Wert der aktuellen Gesamtdialysedosierung KT_TI, der bei der abgelaufenen Behandlungszeit T_I zugeführt wurde, und

o mindestens eine zwischen einer voraussichtlichen restlichen Behandlungsvorgangszeit T_tr und einer voraussichtlichen Gesamtbehandlungszeit T_tot, die zum Erreichen des vorgegebenen Gesamtdialysedosierungswerts KT_p erforderlich ist,

wobei der Controller geeignet ist zum Erzeugen vom Ausgangssteuersignal als Reaktion auf den Vergleich, um eine Fluidentfernungsförderrate aus der zweiten Kammer automatisch zu steuern.

2. Einrichtung nach Anspruch 1, wobei der signifikante Parameter ausgewählt wird aus der Gruppe umfassend:

- die aktuelle Dialysance D_TI oder Clearance K_TI einer Blutbehandlungseinheit, die mit der Einrichtung verbunden ist, für einen spezifischen gelösten Stoff nach einer Zeit T_I, die vom Anfang der Behandlung abgelaufen ist;

- die Konzentration eines Stoffs im Blut eines einer Behandlung unterworfenen Patienten oder die Plasmaleitfähigkeit Cp_TI des Patienten, die zur abgelaufenen Zeit T_I erreicht ist;

- die Dialysedosis KT_TI, die zur abgelaufenen Zeit T_I erreicht ist;

- den Gewichtsverlust WL_TI, der zur abgelaufenen Zeit T_I erreicht ist;

- einen Parameter, der proportional zu oder eine bekannte Funktion von einem oder mehreren der obigen Parameter ist.

3. Einrichtung nach den Ansprüchen 1 oder 2, wobei die gemessenen Informationen ausgewählt werden aus der Gruppe umfassend:

- Leitfähigkeit der Behandlungsflüssigkeit abwärts von der Behandlungseinheit;

- Konzentration eines Stoffs in der Behandlungsflüssigkeit abwärts von der Behandlungseinheit.

4. Einrichtung nach einem der Ansprüche 1 bis 3, wobei der Controller programmiert ist zur Bestimmung der voraussichtlichen restlichen Behandlungsvorgangszeit T_tr als Funktion des Gesamtdialysedosierungswerts KT_p, der aktuellen, vor der Zeit T_I erreichten, Gesamtdialysedosierung KT_TI, und des augenblicklichen Werts der Clearance K_TI oder Dialysance D_TI, der zur Behandlungszeit T_I gemessen wurde.

5. Einrichtung nach einem der Ansprüche 1 bis 3, wobei der Controller programmiert ist zur Bestimmung der voraussichtlichen Gesamtbehandlungszeit T_tot als Funktion des Gesamtdialysedosierwerts KT_p, der aktuellen, vor der Zeit T_I erreichten Gesamtdialysedosierung KT_TI, und der abgelaufenen Behandlungszeit T_I.

6. Einrichtung nach Anspruch 4, wobei der Controller zu jedem Zeitintervall programmiert ist zur Aktualisierung der voraussichtlichen Gesamtbehandlungszeit T_tot als Summe der abgelaufenen Behandlungszeit T_I und des voraussichtlichen Werts der restlichen Behandlungsvorgangszeit T_tr.

7. Einrichtung nach Anspruch 4 oder 5, wobei der vorgegebene Parameter auch einen vorgegebenen Gesamtgewichtsverlust WL_p umfasst, der am Ende der Behandlung erreicht werden soll, wobei der Controller programmiert ist zur Durchführung der folgenden weiteren Schritten zu Zeitintervallen während der Behandlung:

o Bestimmung eines aktuellen gemessenen Gesamtgewichtsverlusts WL_TI, der vor der Zeit T_I erreicht wurde,

o Einstellen einer Fluidentfernungsförderrate UF aus der zweiten Kammer, um einen vorgegebenen Gesamtgewichtsverlust WL_p zu erreichen, im Wesentlichen gleichzeitig zum Erreichen des vorgegebenen Gesamtdialysedosierwerts KT_p.

8. Einrichtung nach Anspruch 7, wobei sie programmiert ist zur kontinuierlichen Steuerung der Ruidentfemungsförderrate als Funktion der voraussichtlichen restlichen Behandlungsvorgangszeit T_tr oder der voraussichtlichen Gesamtbehandlungszeit T_tot.

9. Einrichtung nach Anspruch 8, wobei die Steuerung das Einstellen der Fluidentfernungsförderrate UF_TI zur Zeit T_I wie der vorgegebene Gesamtgewichtsverlust WL_p minus der gemessene Gesamtgewichtsverlust WL_TI zur Zeit T_I, geteilt durch die voraussichtliche restliche Behandlungszeit T_tr, umfasst, nach der Formel:

10. Einrichtung nach Anspruch 8, wobei der Steuerungsschritt das Einstellen der Fluidentfernungsförderrate UF_TI zur Zeit T_I wie den vorgegebenen Gesamtgewichtsverlust WL_p minus der gemessene Gesamtgewichtsverlust WL_TI zur Zeit T_I, geteilt durch eine Differenz zwischen der voraussichtliche Gesamtbehandlungszeit T_tot und der abgelaufenen Behandlungszeit T_I umfasst, nach der Formel:

11. Einrichtung nach einem der Ansprüche 1 bis 10, wobei der Controller programmiert ist zur Neuberechnung und Aktualisierung zu regelmäßigen Zeitintervallen während der Behandlung von der voraussichtlichen Gesamtbehandlungszeit T_tot und/oder der voraussichtlichen restlichen Behandlungszeit T_tr auf Basis des/der neusten Werts/Werte von augenblicklicher Clearance K_TI oder Dialysance D_TI.

12. Einrichtung nach einem der Ansprüche 1 bis 10, wobei sie programmiert ist zur Neuberechnung und Aktualisierung zu regelmäßigen Zeitintervallen während der Behandlung vom aktuellen Gesamtdialysedosierungswert KT_TI, der zur abgelaufenen aktuellen Behandlungszeit T_I ausgegeben wurde.

13. Einrichtung nach Anspruch 1, wobei der augenblickliche Clearancewert K_TI durch die folgenden Unterschritte bestimmt wird:

- Senden mindestens einer ersten Flüssigkeit durch die zweite Kammer der Behandlungseinheit,

- Senden mindestens einer zweiten Flüssigkeit durch die zweite Kammer der Behandlungseinheit, wobei die zweite Flüssigkeit eine andere Leitfähigkeit oder Konzentration für mindestens einen gelösten Stoff als die der ersten Flüssigkeit aufweist,

- Messen der Leitfähigkeits- oder Konzentrationswerte des Stoffs in der Behandlungsflüssigkeit abwärts von der Behandlungseinheit mindestens sowohl für die erste als auch für die zweite Flüssigkeit,

- Berechnen des Werts der augenblicklichen Clearance K_TI oder der augenblicklichen Dialysance D_TI mindestens als Funktion der gemessenen Leitfähigkeits- oder Konzentrationswerte.

14. Einrichtung nach Anspruch 1, wobei der aktuelle Wert der Gesamtdialysedosierung KT_TI, der bei der bestimmten aktuellen Behandlungszeit T_I ausgegeben wurde, als zeitliche Integration der aktuellen Werte der augenblicklichen Clearance K_TI oder der augenblicklichen Dialysance D_TI, die zu den verschiedenen regelmäßigen Zeitintervallen T_I bestimmt wurden, berechnet wird.

15. Einrichtung nach Anspruch 1, wobei der aktuelle Wert der Gesamtdialysedosierung KT_TI, der bei der aktuellen Behandlungszeit T_I ausgegebene wurde, als Produkt der Behandlungszeit T_I durch einen Durchschnittswert der aktuellen augenblicklichen Clearance K_TI oder der augenblicklichen Dialysance D_TI, die zu den verschiedenen regelmäßigen Zeitintervallen T_I bestimmt wurden, berechnet wird.

16. Einrichtung nach Anspruch 12, wobei der Controller programmiert ist zur Steuerung der Fluidentfernungsförderrate aus der zweiten Kammer der Blutbehandlung, wobei die Steuerung das Aufrechterhalten der Fluidentfernungsförderrate UF_TI zur Zeit T_I im Wesentlichen gleich zum Produkt der vorgegebenen Fördermenge R durch den augenblicklichen Clearance- K_TI oder Dialysancewert D_TI, der bei der Behandlungszeit T_I gemessen wurde, umfasst.

17. Einrichtung nach Anspruch 1, wobei der Controller zu jedem Zeitintervall programmiert ist:

- zum Berechnen einer Summe der abgelaufenen Behandlungszeit T_I und dem berechneten Wert der restlichen Behandlungsvorgangszeit T_tr,

- zum Vergleichen der Summe mit einer Minimumbehandlungszeit T_min und mit einer Maximumbehandlungszeit T_max,

- Einstellen einer Gesamtbehandlungszeit T_tot gleich der Minimumbehandlungszeit T_min, wenn die Summe kleiner als die Minimumbehandlungszeit T_min ist,

- Einstellen einer Gesamtbehandlungszeit T_tot gleich der Maximumbehandlungszeit T_max, wenn die Summe größer als die Maximumbehandlungszeit T_max ist,

- Einstellen einer Gesamtbehandlungszeit T_tot gleich der Summe, wenn die Summe weder kleiner als die Minimumbehandlungszeit T_min noch größer als Minimumbehandlungszeit T_max ist.

18. Einrichtung nach Anspruch 17, wobei der vorgegebene Parameter auch einen vorgegebenen, am Ende der Behandlung zu erreichenden Gesamtgewichtsverlust WL_p umfasst, wobei der Controller programmiert ist zur Durchführung der folgenden weiteren Schritten zu Zeitintervallen während der Behandlung:

o Bestimmung von einem aktuellen gemessenen Gesamtgewichtsverlust WL_TI, der vor der Zeit T_I erreicht wurde,

o Einstellen einer Fluidentfernungsförderrate aus der zweiten Kammer, um einen vorgegebenen Gesamtgewichtsverlust WL_p zur Gesamtbehandlungszeit T_tot zu erreichen.

19. Einrichtung nach Anspruch 18, wobei der Controller programmiert ist zur kontinuierlichen Steuerung der Fluidentfernungsförderrate UF_TI zur Zeit T_I als Funktion der Gesamtbehandlungszeit T_tot durch Einstellen der Fluidentfernungsförderrate UF_TI zur Zeit T_I gleich dem voraussichtlichen Gesamtgewichtsverlust WL_p minus dem gemessenen Gewichtsverlust WL_TI zur Zeit T_I geteilt durch die Differenz zwischen der berechneten Gesamtbehandlungszeit T_tot und der abgelaufene Behandlungszeit T_I, nach der Formel:

20. Einrichtung nach Anspruch 18, wobei der Controller programmiert ist zur Neuberechnung und Aktualisierung der Gesamtbehandlungszeit T_tot und/oder der restlichen Behandlungszeit T_tr zu regelmäßigen Zeitintervallen während der Behandlung, auf Basis des/der neusten augenblicklichen gemessenen Werts/Werte von Clearance K_TI oder Dialysance D_TI.

21. Einrichtung nach Anspruch 18, wobei der Controller programmiert ist zur Neuberechnung und Aktualisierung zu regelmäßigen Zeitintervallen während der Behandlung vom aktuellen Wert der Gesamtdialysedosierung KT_TI, die zur abgelaufenen aktuellen Behandlungszeit T_I zugeführt wurde.

22. Einrichtung nach Anspruch 18, wobei der aktuelle Wert der Gesamtdialysedosierung KT_I, der zur bestimmten aktuellen Behandlungszeit T_I ausgegebene wurde, als zeitliche Integration der aktuellen Werte der augenblicklichen Dialysedosierung D_TI, die zu den verschiedenen regelmäßigen Zeitintervallen T_I bestimmt wurden, berechnet wird.

23. Einrichtung nach Anspruch 1 oder 17, wobei der vorgegebene Bezugswert ein Blutleitfähigkeits- oder Konzentrationsziel Cp_end des Patienten umfasst, wobei der Controller programmiert ist zur Steuerung der Leitfähigkeit der Konzentration der zur zweiten Kammer zugeführten Behandlungsflüssigkeit als Funktion des Blutleitfähigkeits- oder Konzentrationsziel Cp_end.

24. Einrichtung nach Anspruch 1, wobei der vorgegebene Bezugswert ein zu erreichendes Blutleitfähigkeits- oder Konzentrationsziel Cp_end des Patienten umfasst, wobei der Controller programmiert ist zum Ändern, wenn erforderlich, zu jedem Zeitintervall der Leitfähigkeit oder Konzentration der zur zweiten Kammer zugeführten Behandlungsflüssigkeit, um eine Blutleitfähigkeit oder Konzentration eines Stoffs zu erhalten, die das Leitfähigkeits- oder Konzentrationsziel Cp_end zur oder vor der voraussichtlichen Gesamtbehandlungszeit T_tot erreicht.

25. Einrichtung nach Anspruch 7, wobei der vorgegebene Bezugswert ein zu erreichendes Blutleitfähigkeits- oder Konzentrationsziel Cp_end des Patienten umfasst, wobei der Controller programmiert ist zum Ändern, wenn erforderlich, zu jedem Zeitintervall der Leitfähigkeit oder Konzentration der zur zweiten Kammer zugeführten Behandlungsflüssigkeit, um eine Blutleitfähigkeit oder Konzentration eines Stoffs zu erhalten, die das Leitfähigkeits- oder Konzentrationsziel Cp_end zur oder vor der voraussichtlichen Gesamtbehandlungszeit T_tot erreicht.

26. Einrichtung nach einem der Ansprüche 1 bis 22, wobei der voraussichtliche Bezugswert ein zu erreichendes Blutleitfähigkeits- oder Konzentrationsziel Cp_end des Patienten umfasst, wobei der Controller programmiert ist zur Durchführung der folgenden Schritte zu jedem Zeitintervall t_I während mindestens eines Teils der Behandlung:

o Bestimmung von einem Blutleitfähigkeits- oder -konzentrationszielbereich Cp_I für das Blut des Patienten, bezüglich einer abgelaufenen Zeit T_I,

o Änderung, wenn erforderlich, von der Leitfähigkeit oder Konzentration für einen Stoff C_d der zur zweiten Kammer zugeführten Behandlungsflüssigkeit, so dass die Plasmaleitfähigkeit des Patienten den Zielbereich Cp_i erreicht.

27. Einrichtung nach Anspruch 26, wobei die Änderung der Behandlungsflüssigkeitsleitfähigkeit oder -konzentration C_d die folgenden Unterschritte umfasst:

i. Bestimmung von einem berechneten Wert C_di der Leitfähigkeit oder Konzentration für einen Stoff C_d als Funktion des Zielbereichs C_pi und der gemessenen augenblicklichen Dialysance oder Clearance D_I oder K_I für die Zeit T_I,

ii. Bringen der Leitfähigkeit oder Konzentration für einen Stoff C_d der zur zweiten Kammer zugeführten Behandlungsflüssigkeit auf den berechneten Wert C_di.

28. Einrichtung nach Anspruch 27, wobei der Bestimmungsschritt die folgenden Formel anwendet:


wobei V₀ das Harnstoffverteilungsvolumen für den Patienten darstellt.

29. Einrichtung nach Anspruch 27, wobei der Bestimmungsschritt die folgenden Formel anwendet:


wobei V₀ das Harnstoffverteilungsvolumen für den Patienten darstellt.

30. Einrichtung nach Anspruch 26, wobei der Controller programmiert ist zur Berechnung des Intervallblutleitfähigkeits- oder -konzentrationsziels Cp_I für das Blut des Patienten bezüglich eines Zeitintervalls t_I nach den folgenden Schritten:

- Bewerten, ob die abgelaufene Behandlungszeit T_i größer oder kleiner als ein vorgegebener Wert Tp ist,

- Zuordnen als Blutzielbereich Cpi = Cp_end + A, wobei A ein positiver Wert ist, wenn Ti kleiner als Tp ist,

- Zuordnen als Blutzielbereich Cpi = Cp_end, wenn Ti größer als oder gleich Tp ist.

31. Einrichtung nach Anspruch 30, wobei der vorgegebene Wert T_p kleiner als T_tot ist.

32. Einrichtung nach Anspruch 31, wobei der vorgegebene Wert T_p gleich T_tot minus eine Stunde ist.

33. Einrichtung nach Anspruch 1, umfassend Messmittel, die mit dem Controller verbunden sind, zur Messung von mindestens einem von:

Leitfähigkeit der Behandlungsflüssigkeit abwärts der Behandlungseinheit; oder

Konzentration eines Stoffs in der Behandlungsflüssigkeit abwärts der Behandlungseinheit.

34. Einrichtung nach Anspruch 1, umfassend Messmittel zur Messung von mindestens einem von:

Leitfähigkeit der Behandlungsflüssigkeit aufwärts der Behandlungseinheit; oder

Konzentration eines Stoffs in der Behandlungsflüssigkeit aufwärts der Behandlungseinheit.

35. Einrichtung nach Anspruch 33, umfassend Messmittel umfassend eine Leitfähigkeitszelle oder einen ionenselektiven Sensor oder einen Harnstoffsensor, die/der an einer Rohrleitung abwärts der Behandlungseinheit betrieben wird.

36. Einrichtung nach Anspruch 34, umfassend Messmittel umfassend eine Leitfähigkeitszelle oder einen ionenselektiven Sensor, die/der an einer Rohrleitung aufwärts von der Behandlungseinheit betrieben wird.

37. Einrichtung nach Anspruch 1, weiter umfassend Eingabemittel zur Eingabe von einem vorgegebenen Bezugswert oder von vorgegebenen Bezugswerte für den oder die signifikanten Parameter.

38. Einrichtung nach Anspruch 1, umfassend eine Ultrafiltrationspumpe mit variabler Geschwindigkeit, wobei der Controller programmiert ist zur Erzeugung eines Steuersignals zur automatischen Steuerung der Fluidentfernungsförderrate aus der zweiten Kammer durch Steuerung der Ultrafiltrationspumpe mit variabler Geschwindigkeit.

39. Einrichtung nach Anspruch 1, wobei der Controller mit einer Alarmvorrichtung verbunden ist, und der Controller programmiert ist zur Aktivierung der Alarmvorrichtung, wenn die voraussichtliche Behandlungsvorgangszeit oder restliche Hemodialysebehandlungszeit nicht innerhalb eines vorbestimmten Bereichs liegen.

40. Einrichtung nach Anspruch 1, wobei der Controller mit einem Anzeigebildschirm verbunden ist, zur Anzeige zu den regelmäßigen Zeitintervallen T_I eines oder mehrerer der Werte der Gruppe umfassend:

- restliche Zeit T_tr,

- Gesamtbehandlungszeit T_tot,

- Clearance- oder Dialysancemessungen zur abgelaufenen Zeit T_I,

- erreichte Dialysedosierung KT_TI nach der Zeit T_I,

- erreichter Gewichtsverlust WL_TI nach der Zeit T_I,

- erreichte Leitfähigkeit des Patienten nach der Zeit T_I,

- vorgegebener Wert für mehrere der signifikanten Parameter,

- einen Wert, der zu einem oder mehreren der obigen Werte proportional ist.

41. Programmspeichermittel umfassend ein Programm für einen programmierbaren Controller einer Blutbehandlungseinrichtung nach Anspruch 1, wobei das Programm, wenn es durch den Controller ausgeführt wird, dem Controller erlaubt, ein Verfahren zur automatischen Steuerung einer oder mehrerer, durch die Einrichtung durchgeführter Operationen auszuführen, wobei das Verfahren die folgenden Schritte umfasst:

- Empfangen einer oder mehrerer Einträge gemessener Information, die während des Behandlungsvorgangs gemessen wurde,

- Berechnen von einem Wert mindestens eines signifikanten Parameters aus der gemessenen Information, der die Entwicklung einer durch die Einrichtung durchgeführten extrakorporalen Blutbehandlung anzeigt,

- Vergleichen des berechneten signifikanten Parameters mit mindestens einem vorgegebenen Bezugswert für denselben Parameter, wobei der vorgegebene Bezugswert den Gesamtdialysedosierwert KT_p, der am Ende der Behandlung erreicht werden soll,

- Erzeugen mindestens eines Ausgangssteuersignals als Reaktion auf den Vergleich, um eine oder mehrere durch die Einrichtung durchgeführten Operationen automatisch zu steuern,

- Bestimmen zu Zeitintervallen während der Behandlung von:

o einem augenblicklichen Wert von Clearance K_TI oder Dialysance D_TI, der zur Behandlungszeit T_I gemessen wurde,

o einem Wert der aktuellen Gesamtdialysedosierung KT_TI, der zur angelaufenen Behandlungszeit T_I zugeführt wurde, und

o mindestens einer zwischen einer voraussichtlichen restlichen Behandlungsvorgangszeit T_tr und einer voraussichtlichen Gesamtbehandlungszeit T_tot, die zum Erreichen des vorgegebenen Gesamtdialysedosierungswerts KT_p erforderlich ist,

wobei der Schritt des Erzeugens des Ausgangssteuersignals als Reaktion auf den Vergleich zur automatischen Steuerung einer Fluidentfernungsförderrate aus der zweiten Kammer vorgesehen ist.

42. Programmspeichermittel nach Anspruch 41, umfassend einen optischen Datenträger und/oder einen magnetischen Datenträger und/oder einen flüchtigen Speicherträger.

Revendications

1. Appareil de traitement de sang, ledit appareil comprenant au moins une unité de traitement comprenant une membrane semi-perméable séparant l'unité de traitement dans un premier compartiment pour la circulation du sang et un deuxième compartiment pour la circulation d'un liquide de traitement, et un contrôleur apte à:

- recevoir une ou plusieurs saisie d'informations mesurées pendant la procédure de traitement,

- calculer à partir desdites informations mesurées au moins un paramètre significatif indiquant le progrès d'un traitement extracorporel de sang réalisé par l'appareil,

- comparer ledit paramètre significatif calculé avec au moins une valeur de référence préétablie pour le même paramètre, la valeur de référence préétablie comprenant la valeur de dosage de dialyse total KT_p à atteindre à la fin du traitement,

- générer au moins un signal de commande de sortie en réponse à ladite comparaison afin de contrôler automatiquement une ou plusieurs opérations réalisées par l'appareil,

ledit contrôleur déterminant à des intervalles de temps pendant le traitement:

o une valeur instantanée de clearance K_T, ou de dialysance D_TI mesurée au temps de traitement T_I,

o une valeur de dosage de dialyse total effectif KT_TI délivrée au temps de traitement écoulé T_I, et

o au moins un entre un temps de procédure restant estimé T_tr et un temps de traitement totale estimé T_tot nécessaire pour atteindre ladite valeur de dosage de dialyse total préétablie KT_p,

le contrôleur étant apte à générer ledit signal de commande de sortie en réponse à ladite comparaison pour commander automatiquement un débit d'élimination de fluide dudit deuxième compartiment.

2. Appareil selon la revendication 1, où le paramètre significatif est un choisi dans le groupe comprenant:

- la dialysance D_TI ou clearance K_TI actuelle d'une unité de traitement de sang associée à l'appareil pour une soluté spécifique après un temps T_I écoulé du début du traitement;

- la concentration d'une substance dans le sang d'un patient soumis à un traitement ou la conductivité plasmatique Cp_TI du patient atteinte au temps écoulé T_I;

- la dose de dialyse KT_TI atteinte au temps écoulé T_I;

- la perte de poids WL_TI atteinte au temps écoulé T_I;

- un paramètre proportionnel ou fonction connue d'un ou plusieurs des paramètres susdits.

3. Appareil selon les revendications 1 ou 2, où l'information mesurée est une choisie dans le groups comprenant:

- conductivité du liquide de traitement en aval de l'unité de traitement;

- concentration d'une substance dans le liquide de traitement en aval de l'unité de traitement.

4. Appareil selon une quelconque des revendications 1 à 3, où ledit contrôleur est programmé pour déterminer le temps de procédure de traitement restant estimé T_tr en fonction de ladite valeur de dosage de dialyse total KT_p, du dosage de dialyse total effectif KT_TI atteint avant le temps T_I et de la valeur instantanée de clearance K_TI ou de dialysance D_TI mesurée au temps de traitement T_I.

5. Appareil selon une quelconque des revendications 1 à 3, où ledit contrôleur est programmé pour déterminer le temps de traitement total T_tot en fonction de ladite valeur de dosage de dialyse total KT_p, du dosage de dialyse total effectif KT_TI atteint avant le temps T_I et du temps de traitement écoulé T_I.

6. Appareil selon la revendication 4, où ledit contrôleur à chaque intervalle de temps est programmé pour mettre à jour le temps de traitement total estimé T_tot en tant que somme du temps de traitement écoulé T_I e de la valeur estimée du temps de procédure de traitement restant T_tr.

7. Appareil selon la revendication 4 ou 5, où ledit paramètre préétabli comprend aussi une perte de poids totale préétablie WL_p à atteindre à la fin du traitement, ledit contrôleur étant programmé pour exécuter les autres étapes suivantes à des intervalles de temps pendant le traitement:

o déterminer une perte de poids totale mesurée actuelle WL_TI atteinte avant le temps T_I,

o régler un débit d'élimination de fluide UF dudit deuxième compartiment afin d'atteindre une perte de poids totale préétablie WL_p substantiellement au même temps que la valeur préétablie de dosage de dialyse total KT_p est atteinte.

8. Appareil selon la revendication 7, où il est programmé pour commander en continu le débit d'élimination de fluide en fonction du temps de procédure de traitement restant estimé T_tr ou du temps de traitement total estimé T_tot.

9. Appareil selon la revendication 8, où ladite commande comprend le réglage du débit d'élimination de fluide UF_TI au temps T_I égal à la perte de poids totale préétablie WL_p moins la perte de poids totale mesurée WL_TI au temps T_I, divisé par le temps de traitement restant estimé T_tr, selon la formule:

10. Appareil selon la revendication 8, où ladite étape de commande comprend le réglage du débit d'élimination de fluide UF_TI au temps T_I égal à la perte de poids totale préétablie WL_p moins la perte de poids totale mesurée WL_TI au temps T_I, divisé par une différence entre le temps de traitement total estimé T_tot et le temps de traitement écoulé T_t, selon la formule:

11. Appareil selon une quelconque des revendications 1 à 10, où le contrôleur est programmé pour recalculer et mettre à jour à des intervalles de temps réguliers pendant le traitement le temps de traitement total estimé T_tot et/ou le temps de traitement restant estimé T_tr sur la base de la valeur ou des valeurs les plus récentes de clearance K_TI ou dialysance D_TI instantanée.

12. Appareil selon une quelconque des revendications 1 à 10, où il est programmé pour recalculer et mettre à jour à des intervalles de temps réguliers pendant le traitement la valeur de dosage de dialyse total effectif KT_TI délivré au temps de traitement effectif écoulé T_I.

13. Appareil selon la revendication 1, où la valeur de clearance instantanée K_TI ou la valeur de dialysance instantanée D_TI est déterminée au temps de traitement T_i au moyen des sous-étapes suivantes:

- envoyer au moins un premier liquide à travers le deuxième compartiment de l'unité de traitement,

- envoyer au moins un deuxième liquide à travers le deuxième compartiment de l'unité de traitement, le deuxième liquide ayant une conductivité ou concentration pour au moins un soluté différente de celle du premier liquide,

- mesurer les valeurs de conductivité ou concentration de ladite substance dans le liquide de traitement en aval de l'unité de traitement au moins pour ledit premier et pour ledit deuxième liquide,

- calculer la valeur de la clearance instantanée K_TI ou de la dialysance instantanée D_TI au moins en fonction desdites valeurs de conductivité ou concentration mesurées.

14. Appareil selon la revendication 1, où la valeur de dosage de dialyse total effectif KT_TI délivrée au temps de traitement effectif déterminé T_I est calculée en tant que intégration temporelle des valeurs effectives de clearance instantanée K_TI ou de dialysance instantanée D_TI déterminées aux intervalles de temps réguliers T_I.

15. Appareil selon la revendication 1, où la valeur effective de dosage de dialyse total KT_TI délivrée au temps de traitement effective T_I est calculée en tant que produit du temps de traitement T_I par une valeur moyenne de clearance instantanée effective K_TI ou de dialysance instantanée D_TI, mesurées aux intervalles de temps réguliers T_I.

16. Appareil selon la revendication 12, où ledit contrôleur est programmer pour commander le débit d'élimination de fluide du deuxième compartiment de l'unité de traitement de sang, ladite commande comprenant le réglage dudit débit d'élimination de fluide UF_TI au temps T_I substantiellement égal au produit dudit débit préétabli R par la valeur de clearance instantanée K_TI ou de dialysance instantanée D_TI mesurée au temps de traitement T_I.

17. Appareil selon la revendication 1, où ledit contrôleur à chaque intervalle de temps est programmé pour:

- calculer une somme du temps de traitement écoulé T_I et de la valeur calculée du temps de procédure de traitement restant T_tr,

- comparer ladite somme avec un temps de traitement minimum T_min et avec un temps de traitement maximum T_max,

- régler un temps de traitement total T_tot égal au temps de traitement minimum T_min si ladite somme est inférieure au temps de traitement minimum T_min,

- régler un temps de traitement total T_tot égal au temps de traitement maximum T_max si ladite somme est supérieure au temps de traitement maximum T_max,

- régler un temps de traitement total T_tot égal à ladite somme si la somme est ni inférieure au temps de traitement minimum T_min ni supérieure au temps de traitement minimum T_max.

18. Appareil selon la revendication 17, où ledit paramètre préétabli comprend aussi une perte de poids totale préétablie WL_p à atteindre à la fin du traitement, ledit contrôleur étant programmé pour exécuter les autres étapes suivantes à des intervalles de temps pendant le traitement:

o déterminer une perte de poids totale mesurée actuelle WL_TI atteinte avant le temps T_I,

o régler un débit d'élimination de fluide dudit deuxième compartiment afin d'atteindre une perte de poids totale préétablie WL_p audit temps de traitement total T_tot.

19. Appareil selon la revendication 18, où le contrôleur est programmé pour commander en continu le débit d'élimination de fluide UF_TI au temps T_I en fonction du temps de traitement total estimé T_tot en réglant le débit d'élimination de fluide UF_TI au temps T_I égal à la perte de poids totale estimée WL_p moins la perte de poids mesurée WL_TI au temps T_I divisé par la différence entre le temps de traitement total calculé T_tot et le temps de traitement écoulé T_I, selon la formule:

20. Appareil selon la revendication 18, où le contrôleur est programmé pour recalculer et mettre à jour le temps de traitement total T_tot et/ou le temps de traitement restant T_tr à des intervalles de temps réguliers pendant le traitement, sur la base de la valeur ou des valeurs mesurées instantanées les plus récentes de clearance K_TI ou dialysance D_TI instantanée.

21. Appareil selon la revendication 18, où le contrôleur est programmé pour recalculer et mettre à jour à des intervalles de temps réguliers pendant le traitement la valeur de dosage de dialyse total effectif KT_TI délivré au temps de traitement effectif écoulé T_I.

22. Appareil selon la revendication 18, où la valeur de dosage de dialyse total effectif KT_TI délivrée au temps de traitement effectif déterminé T_I est calculée en tant que intégration temporelle des valeurs instantanées effectives de dosage de dialyse D_TI déterminées aux intervalles de temps réguliers T_I.

23. Appareil selon la revendication 1 ou 17, où la valeur de référence préétablie comprend une conductivité ou concentration cible Cp_end du sang du patient, ledit contrôleur étant programmé pour commander la conductivité ou concentration du liquide de traitement entrant dans le deuxième compartiment en fonction de ladite conductivité out concentration cible dans le sang Cp_end.

24. Appareil selon la revendication 1, où la valeur de référence préétablie comprend une conductivité ou concentration cible Cp_end à atteindre dans le sang du patient, ledit contrôleur étant programmé pour modifier, si nécessaire, à chaque intervalle de temps, la conductivité ou concentration du liquide de traitement entrant le deuxième compartiment de sorte à obtenir une conductivité ou concentration dans le sang d'une substance qui atteint ladite conductivité ou concentration cible Cp_end audit ou avant ledit temps de traitement total estimé T_tot.

25. Appareil selon la revendication 7, où la valeur de référence préétablie comprend une conductivité ou concentration cible Cp_end à atteindre dans le sang du patient, ledit contrôleur étant programmé pour modifier, si nécessaire, à chaque intervalle de temps, la conductivité ou concentration du liquide de traitement entrant le deuxième compartiment de sorte à obtenir une conductivité ou concentration dans le sang d'une substance qui atteint ladite conductivité ou concentration cible Cp_end audit ou avant ledit temps de traitement total estimé T_tot.

26. Appareil selon une quelconque des revendications 1 à 22, où la valeur de référence préétablie comprend une conductivité ou concentration cible Cp_end à atteindre dans le sang du patient, ledit contrôleur étant programmé pour exécuter les étapes suivantes à chaque intervalle de temps t_I pendant au moins une partie dudit traitement:

o déterminer un intervalle cible de conductivité ou concentration dans le sang Cp_I pour le sang du patient, relativement au temps écoulé T_I,

o modifier, si nécessaire, la conductivité ou concentration d'une substance C_d du liquide de traitement entrant dans le deuxième compartiment afin d'obtenir une conductivité plasmatique du patient qui atteint l'intervalle cible Cp_i.

27. Appareil selon la revendication 26, où ladite modification de la conductivité ou concentration du liquide de traitement Cd comprend les sous-étapes suivantes:

i. déterminer une valeur calculée C_di de la conductivité ou concentration d'une substance C_d en fonction de l'intervalle cible C_pi et de la dialysance ou clearance instantanée mesurée D_I ou K_I pour le temps T_I,

ii. porter la conductivité ou concentration d'une substance C_d du liquide de traitement entrant le deuxième compartiment à ladite valeur calculée C_di.

28. Appareil selon la revendication 27, où ladite étape de détermination utilise la formule suivante:


où V₀ représente le volume de distribution d'urée pour le patient.

29. Appareil selon la revendication 27, où ladite étape de détermination utilise la formule suivante:


où V₀ représente le volume de distribution d'urée pour le patient.

30. Appareil selon la revendication 26, où le contrôleur est programmé pour calculer ledit intervalle cible de conductivité ou concentration dans le sang Cp_I pour le sang du patient relativement à un temps écoulé t_I selon les étapes suivantes:

- évaluer si le temps de traitement écoulé T_i est supérieur ou inférieur à une valeur préétablie Tp,

- assigner comme intervalle cible pour le sang Cpi = Cp_end + A, où A est une valeur positive, si T_i est inférieur à T_p,

- assigner comme intervalle cible pour le sang Cpi = Cp_end, si Ti est supérieur ou égal à T_p.

31. Appareil selon la revendication 30, où la valeur préétablie T_p est inférieure à T_tot.

32. Appareil selon la revendication 31, où la valeur préétablie T_p est égal à T_tot moins une heure.

33. Appareil selon la revendication 1, comprenant des moyens de mesure reliés au contrôleur pour mesurer au moins une entre:

conductivité du liquide de traitement en aval de l'unité de traitement; ou

concentration d'une substance dans le liquide de traitement en aval de l'unité de traitement.

34. Appareil selon la revendication 1, comprenant des moyens de mesure d'au moins une entre:

conductivité du liquide de traitement en amont de l'unité de traitement; ou

concentration d'une substance dans le liquide de traitement en amont de l'unité de traitement.

35. Appareil selon la revendication 33, comprenant des moyens de mesure comprenant une cellule de conductivité ou un capteur sélectif aux ions ou un capteur d'urée, installé sur un conduit en aval de l'unité de traitement.

36. Appareil selon la revendication 34, comprenant des moyens de mesure comprenant une cellule de conductivité ou un capteur sélectif aux ions, installé sur un conduit en amont de l'unité de traitement.

37. Appareil selon la revendication 1, comprenant aussi des moyens d'entrée pour saisir une valeur ou des valeurs de référence préétablies pour le paramètre ou les paramètres significatifs.

38. Appareil selon la revendication 1, comprenant une pompe d'ultrafiltration à vitesse variable, où le contrôleur est programmé pour générer un signal de contrôle pour contrôler automatiquement le débit d'élimination de fluide dudit deuxième compartiment en contrôlant la pompe d'ultrafiltration à vitesse variable.

39. Appareil selon la revendication 1, où le contrôleur est associé à un dispositif d'alarme, et le contrôleur est programmé pour activer ledit dispositif d'alarme si le temps de procédure du traitement estimé ou le temps de traitement d'hémodialyse restant ne sont pas dans un intervalle préétabli.

40. Appareil selon la revendication 1, où le contrôleur est associé à un écran de visualisation apte à visualiser aux intervalles de temps T_i une ou plusieurs des valeurs du groups comprenant:

- temps restant T_tr,

- temps de traitement total T_tot,

- mesures de clearance ou dialysance au temps écoulé T_I,

- dosage de dialyse atteint KT_TI après le temps T_I,

- perte de poids atteinte WL_TI après le temps T_I,

- conductivité du patient atteinte après le temps T_I,

- valeur préétablie pour plusieurs paramètres significatifs,

- une valeur proportionnelle à une ou plusieurs des susdites valeurs.

41. Moyen de stockage de programmes comprenant un programme pour un contrôleur programmable d'un appareil de traitement de sang selon la revendication 1, le programme lorsqu'il est exécuté par le contrôleur permettant au contrôleur d'exécuter un procédé pour commander automatiquement une ou plusieurs opérations variables réalisées par l'appareil, ledit procédé comprenant les étapes suivantes:

- recevoir une ou plusieurs saisies d'informations mesurées pendant la procédure de traitement,

- calculer à partir desdites informations mesurées au moins un paramètre significatif indiquant le progrès d'un traitement extracorporel de sang réalisé par l'appareil,

- comparer ledit paramètre significatif calculé avec au moins une valeur de référence préétablie pour le même paramètre, la valeur de référence préétablie comprenant la valeur de dosage de dialyse total KT_p à atteindre à la fin du traitement,

- générer au moins un signal de commande de sortie en réponse à ladite comparaison afin de contrôler automatiquement une ou plusieurs opérations réalisées par l'appareil,

- déterminer à des intervalles de temps pendant le traitement:

o une valeur instantanée de clearance K_TI ou de dialysance D_TI mesurée au temps de traitement T_I,

o une valeur de dosage de dialyse total effectif KT_TI délivrée au temps de traitement écoulé T_I, et

o au moins un entre un temps de procédure restant estimé T_tr et un temps de traitement totale estimé T_tot nécessaire pour atteindre ladite valeur de dosage de dialyse total préétablie KT_p,

où l'étape de générer ledit signal de contrôle de sortie en réponse à ladite comparaison est pour contrôler automatiquement un débit d'élimination de fluide dudit deuxième compartiment.

42. Moyen de stockage de programmes selon la revendication 41, comprenant un support de données optique et/ou un support de données magnétique et/ou un support á mémoire volatile.

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